Omar Kelly: Miami Dolphins have mixed bag of results

What have we learned about the Miami Dolphins (1-3) a quarter of the way through the 2012 season?

Worst luck: The Dolphins have lost back-to-back overtime games in heartbreaking fashion. A 48-yard field goal by Dan Carpenter would have beat the Jets in overtime, and better coverage from cornerback Sean Smith on a fourth-and-10 pass late in the fourth quarter of last Sunday's 24-21 overtime loss to the Cardinals was crippling. The Dolphins clearly must learn how to finish off close games.

Biggest surprise: Brian Hartline has stepped to the forefront as a reliable starting receiver, consistently providing big plays for rookie quarterback Ryan Tannehill. Hartline's a perfect fit for the west coast offense, and these two are developing chemistry. But now that Hartline leads the NFL with 455 receiving yards there's no more sneaking under the radar.

Biggest disappointment: Jake Long, a four-time Pro Bowler, was on his way to the Hall of Fame based on his dominance during his first three seasons. But he's looked human lately since last year. Long allowed his three sacks in four games last Sunday. It appears he's no longer the left tackle Miami can leave on an island by himself.

Biggest bargain? Fullback Jorvorskie Lane, who will earn a $390,000 base salary this season, was signed in the offseason to serve as a camp body. But after four games he's developed into one of the offense's most vital components. Lane's prowess as a lead blocker has helped the Dolphins become a dominant rushing team (4.6 per carry). His ability to bulldoze defenders has led to two short-yardage scores and a successful two-point conversion.

What's the return policy? Legedu Naanee, one of the few free agent additions that made the team, earned a starting spot with strong performances during Miami's OTAs and training camp. But that was with David Garrard as his quarterback. The six-year veteran has no chemistry with Tannehill and it shows. Bad things - two interceptions and one fumble - have happened on passes Tannehill has thrown Naanee. He's played in 121 offensive snaps for the Dolphins and is rated 145th by ProFootballFocus.com when evaluating all 148 receivers who have stepped on an NFL field this season.

By the number: Miami's dominance against the run (2.4 yards per carry) has made the opposition one dimensional every Sunday. Team have been forced to abandon the ground game and lean on their passing attack against the Dolphins. The front seven's success against the run the three years justifies the money and draft picks used on the defense by the old regime. After stuffing Cardinals rusher Ryan Williams to 26 yards (29 for team), the run defense is number one in the NFL.

Stock rising: Koa Misi has blossomed as a 4-3 strongside linebacker, removing himself from Miami Dolphins draft bust territory. The 2010 second-round pick has been consistently around the ball (27 tackles) and he has contributed 1.5 sacks and one forced fumble already this season. But he needs to improve in pass coverage, which has been a perceived strength. Opposing tight ends are dominating the Dolphins because of poor coverage.

Stock falling: Richard Marshall earned a starting spot because he was more consistent than Vontae Davis during training camp. Davis got traded to Indianapolis for draft picks, and Marshall's consistency disappeared. He's presently battling back issues, but opposing quarterbacks have a 101.2 quarterback rating when throwing his way, and he's been penalized a team-leading four times. It doesn't help that cornerback is a position the Dolphins are thin at.

How much again? The Dolphins are projected to have $45-50 million in salary cap space this offseason, but Miami also has a ton of free agents the team would benefit from re-signing. Long, tailback Reggie Bush, defensive tackle Randy Starks, Smith, Hartline and tight end Anthony Fasano won't come cheap. Re-signing those six relatively young players - or finding upgrades in free agency in 2013 - will probably cost the Dolphins north of $30 million.

Rookie report: Tannehill has had some positive moments, especially his rookie record-setting performance against Arizona last Sunday. But his 66.4 quarterback rating has him ranked 31st in the NFL, and puts him ahead of only fellow rookie Brandon Weeden. The Dolphins' first-round pick must improve his completion percentage (55.9) and cut down the turnovers (six interceptions) to improve. Jonathan Martin is settling in nicely as the starting right tackle (one sack allowed). And fellow draft picks Olivier Vernon (seven tackles, half a sack, one forced fumble), Lamar Miller (126 rushing yards and one touchdown on 23 carries) and Kheeston Randall (three tackles) have flashed from time-to-time. Tight end Michael Egnew, Miami's third-round pick, and receiver Rishard Matthews, a seventh-rounder, haven't played in a game yet. But return specialist Marcus Thigpen and Lane, who were both undrafted gems, have been pleasant surprises.